Method for monitoring ue reachability in wireless communication system, and device for same

A method for monitoring User Equipment (UE) reachability in a wireless communication system, the method performed by a first network node device, the first network device including a transceiver, a processor and a memory, the method comprising:

• receiving a first message from a second network node;
• when a UE reachability related information is included in the first message, setting an Active Time for the UE using the UE reachability related information;
• after receiving the first message, monitoring the UE when the UE will become reachable;
• and
• based on the monitoring, transmitting a second message regarding the UE reachability to a server,
• wherein the UE reachability related information is used for setting the Active Time of the UE so that the UE stays reachable to allow the server to deliver a downlink data to the UE.

A first network node for monitoring User Equipment (UE) reachability in a wireless communication system, the first network node comprising:

• a transceiver;
• and
• a processor for controlling the transceiver,
• wherein the processor is configured to:
• receive a first message from a second network node;
• when a UE reachability related information is included in the first message, setting an Active Time for the UE using the UE reachability related information;
• after receiving the first message, monitoring the UE when the UE will become reachable;
• and
• based on the monitoring, transmitting a second message regarding the UE reachability to a server,
• wherein the UE reachability related information is used for setting the Active Time of the UE so that the UE stays reachable to allow the server to deliver a downlink data to the UE.